From time to time, orthopedic implants such as knee or hip replacements and the tissue around the implant become infected. The infected implant is removed, and it conventionally takes 4 to 8 weeks or more to adequately treat the infection during which time the implant site is kept immobile. This may cause unused muscles to contract and shrink the space previously occupied by the joint implant that connected articulating bones such as the space between the shortened end of a femur and the acetabulum on the hip bone in the case of a hip replacement.
To prevent the shrinkage of the implant site, one treatment is to replace the infected permanent implant with a temporary implant or spacer made of an antibiotic-filled cement. The spacer preserves the distance between the adjoining bones so that muscle cannot overly contract while the infection is being cleared from the implant site. Additionally, once positioned within the body, the antibiotic leaches out of the spacer to treat tissue near the spacer and prevent further spreading of the infection. Once the infection is cleared, the spacer is replaced with a new permanent implant.
Some known spacers are pre-made and are provided to the physicians performing the surgery. This usually provides little or no opportunity for the physicians to significantly customize or modify the spacer to match the size of a patient's implant site during the surgical procedures for implanting the spacer.
Other spacers are molded by the physicians by filling molds with curable cement during the surgical procedure. In these cases, when hard molds are used, substantial customization is not possible when the wrong size mold is provided. Also, relatively cumbersome, time consuming, and messy procedures are used to fill the molds. For instance, such hard molds are usually filled by pouring the antibiotic filled cement into mold pieces and then placing the cement into all spaces in the mold by using a spoon or spatula.
Other known relatively soft silicone spacer molds are enclosed for injecting cement into the mold from a cement gun with a nozzle. To fill all of the spaces in the enclosed mold, extra time and effort by the physician is required to shift the nozzle of the cement gun in different directions within the mold. Thus, a spacer mold is desired that permits physicians to easily select and adjust the size of the spacer mold even during surgical procedures, and efficiently and cleanly fill the spacer mold.